Heart Rate Monitoring: Using a medical grade testing algorithm for the resting heart rate, the device monitors your heart time in real time, and constantly traces any changes in your heart rate. Sleep Monitoring: Your sleep will be monitored throughout the night, until you are woken up by a morning call by vibration. The device offers you intimate companionship around the clock. Step Counting: Faithfully recording your running data and tracks, the device helps you manage your data to provide guidance for your exercise plan. Your daily sports activities like walking, jogging, cycling, etc., will be automatically detected. What's more, the device employs a learning algorithm, the more you use it, the more precise the data will be. Sedentary Reminder: Take a rest to avoid fatigue! It has sedentary reminder function to keep fit! Alarm clock reminder: Built-in silent vibration mode, a silent remind alarm that gently vibrates to remind you at your desired time without disturbing your partner. Compatibility Support Android 4.4 or above, IOS7.1 or above. Note: How to set time? Once paired, the clock automatically syncs to your phone's time zone. Why the item doesn't sync to app? Make sure the watch is connect with your phone. Then pull down the main page to refresh. Why my tracker did not monitor my sleep? Make sure the watch is been connected when sleep. Otherwise the watch will not monitor sleep. Why the item stopped working after a day? When you recieve the watch, the battery may be just 10%. Please charge it first. Why does the band not stay on the wrist? There is 2 ways to wear the band. Please try another one.